全文获取类型
收费全文 | 5181篇 |
免费 | 267篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 133篇 |
妇产科学 | 231篇 |
基础医学 | 674篇 |
口腔科学 | 277篇 |
临床医学 | 479篇 |
内科学 | 1202篇 |
皮肤病学 | 66篇 |
神经病学 | 575篇 |
特种医学 | 118篇 |
外科学 | 689篇 |
综合类 | 23篇 |
一般理论 | 1篇 |
预防医学 | 210篇 |
眼科学 | 107篇 |
药学 | 260篇 |
中国医学 | 9篇 |
肿瘤学 | 342篇 |
出版年
2023年 | 24篇 |
2022年 | 68篇 |
2021年 | 119篇 |
2020年 | 75篇 |
2019年 | 122篇 |
2018年 | 158篇 |
2017年 | 115篇 |
2016年 | 136篇 |
2015年 | 155篇 |
2014年 | 199篇 |
2013年 | 276篇 |
2012年 | 390篇 |
2011年 | 402篇 |
2010年 | 253篇 |
2009年 | 214篇 |
2008年 | 343篇 |
2007年 | 344篇 |
2006年 | 360篇 |
2005年 | 283篇 |
2004年 | 241篇 |
2003年 | 253篇 |
2002年 | 230篇 |
2001年 | 62篇 |
2000年 | 33篇 |
1999年 | 38篇 |
1998年 | 50篇 |
1997年 | 54篇 |
1996年 | 34篇 |
1995年 | 32篇 |
1994年 | 23篇 |
1993年 | 24篇 |
1992年 | 36篇 |
1991年 | 29篇 |
1990年 | 24篇 |
1989年 | 24篇 |
1988年 | 20篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 15篇 |
1984年 | 20篇 |
1983年 | 14篇 |
1982年 | 14篇 |
1981年 | 13篇 |
1980年 | 14篇 |
1979年 | 8篇 |
1978年 | 13篇 |
1977年 | 12篇 |
1976年 | 10篇 |
1975年 | 8篇 |
1974年 | 13篇 |
排序方式: 共有5473条查询结果,搜索用时 15 毫秒
51.
Valeria Masciullo Tommaso Susini Alessandra Zamparelli Alessandro Bovicelli Corrado Minimo Daniela Massi Gianluigi Taddei Nicola Maggiano Pierandrea De Iaco Marcello Ceccaroni Luciano Bovicelli Gianni Amunni Salvatore Mancuso Giovanni Scambia Antonio Giordano 《Clinical cancer research》2003,9(14):5332-5338
PURPOSE: p27(Kip1) is a member of the Cip1/Kip1 family of cyclin-dependent kinase inhibitors and is a potential tumor suppressor gene. Low levels of p27 are associated with poor prognosis in a variety of gynecological tumors, including breast, ovarian, and cervical carcinomas. The role of p27 in endometrial cancer remains controversial. EXPERIMENTAL DESIGN: In the present study, p27 protein expression was investigated by immunohistochemistry in a series of 217 endometrial adenocarcinomas and, where present, in synchronous normal endometrium, simple and complex hyperplasia (with or without atypia), and cystic atrophy. The relationship between p27 expression and clinical outcome was also evaluated. RESULTS: Immunohistochemical analysis revealed a significant loss of p27 expression from normal (33%) through hyperplastic endometrium (50%) to endometrial adenocarcinomas (71%; P = 0.001). In addition to nuclear staining, cytoplasmic localization of p27 was noted in 193 (91%) of 217 specimens examined. When the clinical outcome of the patients was evaluated in relation to p27 status, we found no significant correlation between the presence of p27 staining and clinicopathological parameters or survival. CONCLUSIONS: These data indicate that p27 expression could progressively decrease from normal endometrium through hyperplastic endometrium to invasive endometrial carcinomas, suggesting that loss of this tumor suppressor may represent a novel and distinct molecular alteration involved in estrogen-related endometrial adenocarcinomas (type I). Despite the suggested role of the p27 protein in determining the prognosis of several human tumors, it was not found to be a predictor of clinical outcome in this large group of patients with endometrial cancer. 相似文献
52.
Mauro Calvani Claudia Alessandri Giuseppe Paolone Luciano Rosengard Antonino Di Caro David De Franco 《Pediatric allergy and immunology》1997,8(2):91-96
It is currently accepted that vinil infections may influence the development of atopy. In the present study we evaluated serum IgE levels as well as the prevalence of symptom-, indicative of utopic disease and EBV antibodies in 353 children aged from I month to 19 years. Antibodies against EBV were detected by immunofluorescence. IgE levels in serum were measured by en/. yme imimmoassay. Dividing ihe study population according to EBV seropositivity and age, we noted that the prevalence of high IgE levels (> 2 s. d.) was, in total, more frequent in the EBV negative (32. 9%) than in the positive subjects (27. 6%). Interestingly, this higher prevalence was found only in the groups aged under six, especially in the 7 to 29 month group, where it was statistically significant (p=0.037), whereas in the 6-19 year group the situation was reversed. Furthermore, selecting only the atopic children younger than 3 years of age with high IgE levels and clinical symptoms of atopy (wheezing and/or dermatitis) it was possible to demonstrate lower EBV seropositivity compared with the normal IgE controls for each group, even though these differences were not statistically significant. In conclusion, the results of our study suggest that, in our selected population, EBV infection in the first years of life is associated with a lower prevalence of high IgE levels. 相似文献
53.
The intestinal ecosystem in chronic functional constipation 总被引:3,自引:0,他引:3
G Zoppi M Cinquetti A Luciano A Benini A Muner E Bertazzoni Minelli 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(8):836-841
Chronic functional constipation is common in infants, and the bacterial composition of stools in this condition is not known. The study aims were to: (i) investigate the composition of the intestinal ecosystem in chronic functional constipation; (ii) establish whether the addition of the water-holding agent calcium polycarbophil to the diet induces an improvement in constipation; and (iii) determine the composition of the intestinal ecosystem after the use of this agent. In total, 42 children (20F, 22M; mean age: 8.6±2.9y) were studied. Twenty-eight children with functional chronic constipation without anatomical disorders were treated double-blind in random sequence for 1 month with an oral preparation of calcium polycarbophil (0.62g /twice daily) or placebo. Intestinal flora composition was evaluated by standard microbiological methods and biochemical assays on faecal samples collected before and after treatment. Fourteen healthy children were studied as controls. The results show that (i) the constipated children presented a significant increase in clostridia and bifidobacteria in faeces compared to healthy subjects-different species of clostridia and enterobacteriaceae were frequently isolated; no generalized overgrowth was observed; Clostridia outnumbered bacteroides and E. coli mean counts by 2-3log, while bacteroides and E. coli counts were similar (5-6 log10/g fresh faeces); these intestinal disturbances could be defined as a dysbiosis, i.e. a quantitative alteration in the relative proportions of certain intestinal bacterial species. (ii) Clinical resolution of constipation was achieved only in 43% of treated children and an improvement in 21% (one bowel movement every 2 d). (iii) Calcium polycarbophil treatment induced no significant changes in the composition of the intestinal ecosystem, nor in blood chemistry parameters. 相似文献
54.
The relationship of serum-eosinophil cationic protein and eosinophil count to disease activity in children with bronchial asthma 总被引:1,自引:0,他引:1
55.
Ricardo Marcos Pautassi Carla Melloni Luciano Federico Ponce Juan Carlos Molina 《Alcohol》2005,36(2):99-105
Rodents are particularly prone to acquire associative memories during early stages of life. Yet, very little is known about how ethanol interacts with simultaneous associative learning acquired during postabsorptive periods. We have recently observed that preweanling rats avoid lemon odor previously paired with the intraoral infusion of a sapid sweet solution, a result likely to be caused by aversive consequences inherent to this procedure. Two experiments were conducted to analyze the effects of acute ethanol upon the acquisition of this avoidance response. Fourteen-day-old Wistar rats were intragastrically administered with ethanol (0.0, 0.25, 0.5, or 1.25 g/kg) and then exposed for 5 min to a lemon-scented chamber while being intraorally infused with sucrose (12% vol/vol). Four of such pairings were conducted immediately after ethanol administration. Control pups experienced these stimuli in an unrelated fashion. On postnatal day 15 animals were tested in a 5-min, two-way odor-preference test. Pups administered with vehicle during the acquisition phase exhibited a strong aversion to the lemon odor relative to control subjects. This avoidance response was reduced in pups that received 0.5 and 1.25 g/kg doses, whereas it completely vanished in those that received 0.25 g/kg dose. In a second experiment it was observed that, 10 min after the administration, blood ethanol concentrations attained with the 0.25, 0.5, and 1.25 g/kg doses were 11, 39, and 83 mg%, respectively. These data indicate that a very low dose of ethanol is able to counteract early aversive associative learning, a result likely to be mediated by anxiolytic properties of ethanol. 相似文献
56.
G. Bigatti N. Segers W. Boeckx L. Gruft A. Mariani I. Brosens 《Gynecological surgery》2006,3(3):175-179
This study was designed to test the effect of recombinant tissue-type plasminogen activator (rt-PA) in reducing adhesion formation and to observe its influence on peritoneal neoangiogenesis. In 20 Wistar rats, a 4-cm midline incision was made, and a square piece of Silastic, 0.5×0.5 cm and 0.2 mm thick, was fixed on the right side of the peritoneum with two separate angular stitches of nylon 9/O. The rats were randomized into two groups of 10 animals each. In the first group we injected 0.2 mg of rt-PA intraperitoneally three times a day. The second group of 10 rats was used as a control group. Each rat was reoperated on day 12. Intraperitoneal injection of rt-PA seemed not to affect adhesion formation, as a 100% adhesion rate was reported in the treated group compared with 90% of the control group. The results showed that rt-PA acts on the neoangiogenesis involved in postsurgical adhesion formation by reducing the size and length of the vessels. This action seems to slow down peritoneal healing with a negative effect on postsurgical adhesion prevention. 相似文献
57.
Schlaff W. D Carson S. A Luciano A 《世界核心医学期刊文摘》2006,2(6):13-13
目的:与亮脯利特比较,醋酸甲孕酮皮下注射(DMPA-SC104)治疗子宫内膜异位症的有效性和安全性。设计:3期多中心、随机、评价者盲法、对照比较试验。机构:加拿大和美国的临床试验点。患者:274例手术诊断的子宫内膜异位症妇女。干预:每3个月肌注DMPA-SC(104mg)或亮脯利特(11.25mg),共6个月。治疗后随访12个月。主要观察指标:5种子宫内膜异位症症状或体征的减轻(痛经、性交困难、盆腔痛、盆腔触痛、盆腔硬化);骨密度(BMD)改变、低雌激素的症状、出血及体重的变化。结果:DMPA-SC104,在治疗末(6个月)减轻5种子宫内膜异位症症状或体征的4种,在12个月随访末(18个月)减轻全部5种症状,与亮脯利特统计学上效果相当。DMPA-SC104组患者显示在6个月较亮脯利特有更少的BMD损失,在随访的12个月又回到基线水平。 相似文献
58.
BNP and ANP as diagnostic and predictive markers in heart failure with left ventricular systolic dysfunction. 总被引:3,自引:0,他引:3
Luiz Menezes Falc?o Fausto Pinto Luciano Ravara Peter Adriaan van Zwieten 《Journal of the renin-angiotensin-aldosterone system》2004,5(3):121-129
BACKGROUND: The prevalence of chronic heart failure (CHF) with systolic dysfunction is increasing. Plasma natriuretic peptides have been envisaged as diagnostic and predictive markers. AIMS: To investigate the relationship between the levels of B-type natriuretic peptide (BNP) and A-type natriuretic peptide (ANP) and the clinical and functional parameters of CHF in outpatients with CHF at baseline, compared with normal healthy controls; to find out the differences in a randomised controlled trial between patients treated with an angiotensin-converting enzyme (ACE) inhibitor, captopril, or an angiotensin receptor blocker (ARB), irbesartan. These differences were assessed throughout the six-month treatment period and at the sixth month. METHODS: Plasma BNP (pmol/L) and ANP (pmol/L) were determined in 68 hypertensive patients with dilated cardiomyopathy, NYHA class III-IV and ejection fraction (EF) < or = 40%, and in 26 normal controls. Statistical analysis for BNP and ANP was done by Students t-test. The patient group was randomly subdivided into two subgroups of 34 patients, each treated with either an ARB, irbesartan, or an ACE inhibitor (ACE-I), captopril. BNP and ANP were measured in both subsamples and correlated with clinical, functional and neurohormonal parameters throughout a follow-up period of six months and at the sixth month. RESULTS: The mean EF in the patient sample was 33.43+/-6.52% and in the controls was 61.96 +/-3.53% (p=0.000). The mean BNP (pmol/L) in patients was 44.78+/-54.36 and in the controls was 7.12+/-8.28 (p=0.000) and the mean ANP (pmol/L) was 30.32+/-25.97 in patients and 11.18+/-7.92 in controls (p=0.000). A statistically significant difference was found between patients and healthy controls. Significant correlations were found between natriuretic peptides and EF. Between the baseline phase and the sixth month, BNP and ANP decreased significantly in the ARB group. At the sixth month, both BNP and ANP were lower in the ARB group. Evidence of clinical benefit was found with both ARB or ACE-I treatment throughout the six months, with patients moving from classes III and IV to class II NYHA. Improvement of EF was also found, with transition of patients with lower EF (even <30%) to higher values. EF was higher in the ARB group at the sixth month. CONCLUSIONS: BNP and ANP can be useful diagnostic tools in hypertensive CHF patients with moderate-to-severe LV dysfunction. The decrease in BNP and ANP in the ARB group throughout six months, as well as the lower value at the sixth month, suggest a prognostic value of these parameters. 相似文献
59.
G. Decorti Luigi Candussio Fiora Bartoli Klugmann Antonella Strohmayer Maria Pia Mucci Alessandro Mosco Luciano Baldini 《Cancer chemotherapy and pharmacology》1997,40(4):363-366
It has been proven that the anthracyclines induce an important, noncytotoxic histamine release from rat peritoneal mast cells.
As mast cells derived from different tissues exhibit marked heterogeneity, the effect of Adriamycin in comparison with other
antineoplastic agents was tested on fragments of the right heart auricle, which contain a great number of mast cells. In this
experimental model, Adriamycin induced a dose-dependent histamine release that was significantly limited by the antiexocytotic
drug sodium cromoglycate. The antineoplastic agents cisplatin and 5-fluorouracil, in contrast, did not provoke any comparable
histamine release. In the formulation employed in clinical settings, paclitaxel was also capable of inducing a histamine release
comparable with that of Adriamycin; the exocytotic activity, however, was also evident when the tissue fragments were treated
with Cremophor EL alone, without the addition of paclitaxel, whereas treatment of samples with paclitaxel dissolved in ethanol
did not induce any releasing action. These data thus suggest that the secretory activity should be ascribed to the solvent
Cremophor EL and not to paclitaxel. The release of histamine induced by paclitaxel in Cremophor EL/ethanol was also limited
by sodium cromoglycate. These results again indicate that histamine release from mast cells derived not only from the peritoneal
cavity but also from the cardiac tissue could play a role in the cardiotoxicity of anthracyclines and of paclitaxel in the
clinically employed formulation.
Received: 18 August 1996 / Accepted: 22 December 1996 相似文献
60.
Luca Ferrari Francesca Fumagalli Nicoletta Rizzi Elisa Grandi Serena Vailati Michele Manoni Matteo Ottoboni Federica Cheli Luciano Pinotti 《Toxins》2022,14(11)
Aflatoxins (AFs) remain the main concern for the agricultural and dairy industries due to their effects on the performances and quality of livestock production. Aflatoxins are always unavoidable and should be monitored. The objective of this paper is to bring to light a significant volume of data on AF contamination in several animal feed ingredients in Northern Italy. The Regional Breeders Association of Lombardy has been conducting a survey program to monitor mycotoxin contamination in animal feeds, and in this paper, we present data relating to AFB1 contamination. In most cases (95%), the concentrations were low enough to ensure compliance with the European Union’s (EU’s) maximum admitted levels for animal feed ingredients. However, the data show a high variability in AF contamination between different matrices and, within the same matrix, a high variability year over year. High levels of AFs were detected in maize and cotton, especially in the central part of the second decade of this century, i.e., 2015–2018, which has shown a higher risk of AF contamination in feed materials in Northern Italy. Variability due to climate change and the international commodity market affect future prospects to predict the presence of AFs. Supplier monitoring and control and reduced buying of contaminated raw materials, as well as performing analyses of each batch, help reduce AF spread. 相似文献